This invention relates to knit fabrics for use as upholstery material. More particularly, this invention concerns knit fabrics which are stabilized and are substantially non-extensible so as to be suitably used for upholstery purposes.
Upholstery fabrics, such as fabrics to cover furniture and the like, are commonly and conventionally made by weaving the upholstery yarns into the desired pattern and style. To get a variety it is, of course, known to combine different size yarns, color combinations and various weaves including plain, twill, jacquard and dobby; dyeing the yarns and printing also serve to vary the patterns of particular upholstery fabrics.
Besides the reason that weaving of upholstery fabrics is basic and conventional, woven upholstery fabrics are strong and stable, tend to have good abrasion resistance to provide longer use, and are not highly susceptible to yarn pull-out, especially in a tight weave construction. While these advantages of woven upholstery fabrics add to the desirability of the product, there are also a number of disadvantages of woven upholstery fabrics which must be taken into consideration.
After an upholstered piece of furniture, such as a chair, has been sat upon, especially for long periods of time, a distortion of the upholstery fabric is observed. This distortion appears as either a puckered or buckled fabric, or a bubble in the fabric and sometimes a noticeable wrinkle. While this distortion generally is not permanent, the recovery time for the fabric to return to normal is sufficiently long for the fabric to appear somewhat unsightly and disheveled.
Another disadvantage in woven upholstery fabrics is the limitation of the number of rich and heavy type designs and patterns which can be produced. To achieve a more fancy or rich pattern jacquard-woven fabrics are usually necessary. Jacguard weaving is an intricate process which involves a series of punched cards, one card for each pick in the weave, for controlling the actions of the warp threads. The constraint on the equipment required thereby limits the availability of patterns which may evolve.
Recognizing some of these problems associated with woven upholstery fabrics, the upholstery trade has been considering the use of knitted fabrics to overcome the previous troubles. Up to now, however, there has been no penetration of the upholstery fabric market by knit upholstery fabrics. Besides the fact that knit upholstery fabrics would open up a new market for that type of product, there has not been acceptance of knit upholstery fabrics because new problems have been generated in attempting to overcome problems associated with woven upholstery fabrics. For instance, whereas woven fabrics are basically non-extensible, or only slightly extensible, rigid structures, knit fabrics are typically highly extensible or stretchable fabrics. The extensibility of knit fabrics produces a degree of instability in the fabric which allows easy fabric distortion and presentation of an uneven pattern. This uneven pattern and fabric instability is especially prevalant when the knit upholstery fabric is wrapped and fitted around corners of the upholstered item.
Another problem related to knit fabrics is yarn pull-out. Due to the construction of knit fabrics, if a yarn breaks due to snagging, an imperfection, or from wear, that yarn may very easily be raveled from the fabric causing a run in the fabric. The appearance of this fabric with the run is unattractive, while the fabric strength is diminished since the fabric is more susceptible to additional ravelings.
As a means of controlling stretch of knit fabrics and preventing yarn pull-out, it has been heretofore suggested in the art to coat the back of the fabric with a thin latex coating. Whereas the latex coating suitably serves the purpose of preventing the knitted yarns from shifting and from being pulled-out, the stretch control feature is relative and depends upon the characteristics and amounts of coating used. Furthermore, the stretch of the knit fabric, while being controlled by the latex coating, is not reduced to the point of virtual non-extensibility. Moreover, the latex coating adds undesirable stiffness to the knit fabric, and depending on the amount used, also adds unnecessary weight to the fabric. Consequently, use of a thin latex coating on the back of the knit upholstery fabrics has some advantages, but leaves room for further improvement.
On the other hand, it has been suggested that simple stitching operations of knit fabrics, including those which may be used for upholstery, may stabilize the fabric thereby reducing stretch. While this suggestion has merit regarding stabilization, overlooked is the problem of yarn pull-out, especially when the knitted fabric incorporates lay-in yarns. Stitching the knitted fabric does not control yarn pull-out which leaves that fabric in a condition to have runs and yarn raveling when one or more yarns break from various reasons.
There have been further problems in the production of a fabric with a knitted configuration using upholstery yarns designed specifically for woven fabrics. Various yarns of different texture, size, weight, crimp, etc., have been sampled to arrive at a combination of properties which will produce a suitable knit fabric with the desired coarse upholstery look. While to some extent there has been some previous success in making such a fabric per se, there still remains problems of lack of stability and yarn pull-out with which to contend.
It is recognized that the stability of some fabrics, whether woven, nonwoven or knitted, has been improved by combining the primarily unstable fabric with a fusible fabric. For instance, fusible fabrics such as taught in U.S. Pat. Nos. 3,616,150; 3,449,287 and 3,223,575, and British Pat. No. 1,420,261, among others, are used to provide shape retention to sections of articles of wearing apparel, and also to add stiffness, shape, extra padding and boardiness to apparel that otherwise may look lifeless, or to add warmth to garments. However, whereas fusible fabrics are known in the wearing apparel field, heretofore such fusibles have not been combined with upholstery fabric for purposes of stabilization. There are believed to be a number of reasons for this result.
Until very recently, when tests by various fabric manufacturers started on knitted upholstery, all commercial upholstery fabric has been woven. Being woven, the upholstery fabric is intrinsically stable, thus there has been no need to provide further stabilization. Further, there has been no perceptible market for knit upholstery fabric due to problems inherent in knitted products, viz., too much stretch and yarn pull-out, and also due to difficulties in knitting yarns of the proper characteristics to be suitable for upholstery purposes. Without a market for knit upholstery fabrics there is clearly a need for improvements in that type of specialized product which will generate new interest, attention and eventual acceptance of knit upholstery fabrics.